阅读说明：本技术 一种聚合物基氮、磷掺杂石墨化多孔碳的制备方法及应用 (Preparation method and application of polymer-based nitrogen and phosphorus doped graphitized porous carbon ) 是由 董小珍 于 2020-12-16 设计创作，主要内容包括：本发明涉及锂离子电池技术领域,且公开了一种聚合物基氮、磷掺杂石墨化多孔碳,含磷单体的聚(丙烯腈-苯乙烯)共聚物,在预氧化过程中聚苯乙烯热塑性链段气化裂解,产生大量的气体从基体中逸出,留下丰富的孔道结构,聚丙烯腈热固性链段在高温碳化过程中交联固化,形成碳骨架,预氧化过程中,含磷基团的烯基单体热裂解产生磷酸衍生物,具有催化成碳的作用,加速高温碳化过程,提高成炭率,促进碳骨架形成致密而连续的石墨化多孔碳,从而得到孔隙结构丰富、比表面积更大的氮、磷掺杂石墨化多孔碳,丰富的含氮基团和含磷基团提高了石墨化多孔碳的电化学性质、调节孔隙结构和比表面积。(The invention relates to the technical field of lithium ion batteries, and discloses polymer-based nitrogen-phosphorus-doped graphitized porous carbon, wherein a poly (acrylonitrile-styrene) copolymer of a phosphorus-containing monomer is prepared by gasifying and cracking a polystyrene thermoplastic chain segment in a pre-oxidation process to generate a large amount of gas to escape from a matrix and leave a rich pore channel structure, a polyacrylonitrile thermosetting chain segment is crosslinked and cured in a high-temperature carbonization process to form a carbon skeleton, an alkenyl monomer of the phosphorus-containing group is thermally cracked to generate a phosphoric acid derivative in the pre-oxidation process, the phosphoric acid derivative has the function of catalyzing to form carbon, the high-temperature carbonization process is accelerated, the carbon forming rate is improved, and the carbon skeleton is promoted to form compact and continuous graphitized porous carbon, so that the nitrogen-phosphorus-doped graphitized porous carbon with rich pore structures and larger specific surface area is obtained, the electrochemical property, The pore structure and the specific surface area are adjusted.)

1. A polymer-based nitrogen and phosphorus doped graphitized porous carbon is characterized in that: the preparation method of the polymer-based nitrogen and phosphorus doped graphitized porous carbon comprises the following steps:

(1) adding 4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane and triethylamine into a dichloromethane solvent, slowly dropwise adding acryloyl chloride at the temperature of between-10 and-0 ℃, reacting for 5 to 10 hours, wherein the mass ratio of the three is 170-;

(2) adding acrylonitrile, azobisisobutyronitrile and RAFT reagent in a mass ratio of 100:0.75-1.5:0.12-0.18 into an N, N-dimethylformamide solvent, placing the mixture in an atmosphere reaction device, heating the mixture to 75-85 ℃ in a nitrogen atmosphere, and reacting for 10-20 hours to prepare the polyacrylonitrile-based macromolecular chain transfer agent;

(3) adding styrene, acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, polyacrylonitrile-based macromolecular chain transfer agent and initiator azobisisobutyronitrile into an N, N-dimethylformamide solvent, placing the mixture into an atmosphere reaction device, and reacting at 80-90 ℃ for 12-24 hours in a nitrogen atmosphere to prepare a phosphorus monomer-containing poly (acrylonitrile-styrene) copolymer;

(4) the poly (acrylonitrile-styrene) copolymer containing phosphorus monomers is placed in an atmosphere furnace for pre-oxidation and high-temperature carbonization treatment to prepare polymer-based nitrogen and phosphorus doped graphitized porous carbon which is applied to a lithium ion battery cathode material.

2. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the 4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] in the step (1)]Octane having the formula C₅H₉O₅P has a structural formula ofAcryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]Octane derivatives of formula C₈H₁₁O₆P is of the structural formula

3. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the RAFT reagent in the step (2) is s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate with a molecular formula of C₉H₁₄O₄S₃Structural formula is

4. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the atmosphere reaction device in the step (2) comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, a pulley is movably connected to the clamping groove, the pulley is movably connected with a movable plate, a large reaction bottle and a small reaction bottle are arranged above the movable plate, a vent pipe is arranged above the water bath, and two ends of the vent pipe are respectively movably connected with an air inlet valve and an air outlet valve.

5. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the mass ratio of the styrene, the acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, the polyacrylonitrile-based macromolecular chain transfer agent and the azobisisobutyronitrile in the step (3) is 100:20-40:8-15: 0.1-0.2.

6. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the pre-oxidation treatment in the step (4) is an air atmosphere and is performed for 3-6h at the temperature of 220-280 ℃.

7. The polymer-based nitrogen-phosphorus-doped graphitized porous carbon according to claim 1, wherein: the high-temperature carbonization treatment in the step (4) is carried out for 2-3h at the temperature of 750-800 ℃ in a nitrogen atmosphere.

Technical Field

The invention relates to the technical field of lithium ion batteries, in particular to a preparation method and application of polymer-based nitrogen and phosphorus doped graphitized porous carbon.

Background

The lithium ion battery has large energy density and stable cycle performance, is a green and environment-friendly secondary battery, the cathode material of the lithium ion battery which is commercialized at present is mainly a graphite cathode material, but the theoretical specific capacity of graphite carbon is low and is only 370mAh/g, so that the development and application of the lithium ion battery are limited, and the cathode material which is researched in hot spots at present mainly comprises a metal oxide electrode material, a metal alloy cathode material, a silicon-based cathode material and a carbon cathode material, wherein the carbon cathode material such as carbon aerogel, porous carbon, graphene, carbon nano tubes and the like has excellent electrochemical performance, is simple to prepare and wide in source, and is a lithium ion battery cathode material with great development potential.

The porous carbon has a large number of pore channel structures and an ultrahigh specific surface area, and has rich sites for lithium removal and lithium insertion, good electronic conductivity and lithium ion diffusion coefficient, so that the novel porous carbon with excellent performance is synthesized and developed at present to meet the requirement of being applied to a lithium ion battery cathode material and become a research hotspot, wherein the heteroatom doping has the effects of regulating the pore structure and the specific surface area of the porous carbon, regulating the electronic arrangement, improving the electrochemical property and the like through one of the most effective methods of the nitrogen, sulfur, phosphorus and other heteroatom doping.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a preparation method and application of polymer-based nitrogen and phosphorus doped graphitized porous carbon, which has higher specific capacity and excellent rate capability.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of polymer-based nitrogen and phosphorus doped graphitized porous carbon comprises the following steps:

(1) adding a dichloromethane solvent, 4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane and triethylamine into a reaction bottle, slowly dropwise adding acryloyl chloride at the temperature of between-10 and-0 ℃ in a mass ratio of 170-110-100, uniformly stirring for reaction for 5 to 10 hours, carrying out reduced pressure distillation to remove the solvent, washing with diethyl ether, adding methanol and distilled water for recrystallization and purification, and preparing the acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative.

(2) Adding an N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and a RAFT reagent in a mass ratio of 100:0.75-1.5:0.12-0.18 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, heating to 75-85 ℃ in a nitrogen atmosphere, reacting for 10-20h, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the polyacrylonitrile-based macromolecular chain transfer agent.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 12-24h at 80-90 ℃ in the nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the phosphorus monomer-containing poly (acrylonitrile-styrene) copolymer.

(4) The poly (acrylonitrile-styrene) copolymer containing phosphorus monomers is placed in an atmosphere furnace for pre-oxidation and high-temperature carbonization treatment to prepare polymer-based nitrogen and phosphorus doped graphitized porous carbon which is applied to a lithium ion battery cathode material.

Preferably, the 4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] in the step (1)]Octane having the formula C₅H₉O₅P has a structural formula ofAcryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]Octane derivatives of formula C₈H₁₁O₆P is of the structural formula

Preferably, the RAFT agent in the step (2) is s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate with the molecular formula of C₉H₁₄O₄S₃Structural formula is

Preferably, the atmosphere reaction device in step (2) includes a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, a pulley is movably connected to the clamping groove, the pulley is movably connected with a movable plate, a large reaction bottle and a small reaction bottle are arranged above the movable plate, a vent pipe is arranged above the water bath, and two ends of the vent pipe are respectively movably connected with an air inlet valve and an air outlet valve.

Preferably, the mass ratio of the styrene, the acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, the polyacrylonitrile-based macromolecular chain transfer agent and the azobisisobutyronitrile in the step (3) is 100:20-40:8-15: 0.1-0.2.

Preferably, the pre-oxidation treatment in the step (4) is an air atmosphere, and the pre-oxidation is carried out for 3 to 6 hours at the temperature of 220 ℃ and 280 ℃.

Preferably, the high-temperature carbonization treatment in the step (4) is performed in a nitrogen atmosphere at 750-800 ℃ for 2-3 h.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

according to the polymer-based nitrogen and phosphorus doped graphitized porous carbon, acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivatives are used as alkenyl monomers containing phosphorus groups, a polyacrylonitrile-based macromolecular chain transfer agent is used as a nitrogen-containing monomer, and the nitrogen-containing monomer and polystyrene are copolymerized by a high-efficiency controllable RAFT reversible addition-fragmentation chain transfer polymerization method to obtain a poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer, so that nitrogen and phosphorus are controllably and highly distributed in polymer molecular chains.

The polymer-based nitrogen and phosphorus-doped graphitized porous carbon comprises a polystyrene thermoplastic chain segment and a polyacrylonitrile thermosetting chain segment in a poly (acrylonitrile-styrene) copolymer molecular chain of a phosphorus-containing monomer, wherein the polystyrene thermoplastic chain segment is gasified and cracked in the pre-oxidation process to generate a large amount of gas which escapes from a matrix and leave a rich pore channel structure, the polyacrylonitrile thermosetting chain segment is crosslinked and cured in the high-temperature carbonization process to form a carbon skeleton, in the pre-oxidation process, the alkenyl monomer of the phosphorus-containing group is thermally cracked to generate a phosphoric acid derivative, the phosphoric acid derivative has the function of catalyzing to form carbon, the high-temperature carbonization process is accelerated, the carbon forming rate is improved, the carbon skeleton is promoted to form compact and continuous graphitized porous carbon, and thus the nitrogen and phosphorus-doped graphitized porous carbon with rich pore structures and larger specific surface area is obtained, and the rich nitrogen-containing groups and phosphorus-containing groups have good electrochemical properties, pore structures and specific The method has the advantages that the promotion effect is achieved, the doping amount of nitrogen and phosphorus and the controllable adjustment of a pore structure are achieved through the controllable reversible addition-fragmentation chain transfer polymerization method by controlling the amount of the alkenyl monomer containing the phosphorus group and the amount of the polyacrylonitrile-based macromolecular chain transfer agent, and the polymer-based nitrogen and phosphorus doped graphitized porous carbon has higher actual specific capacity and excellent rate capability.

Drawings

FIG. 1 is a schematic view of the structure of an atmosphere reaction apparatus;

FIG. 2 is an enlarged schematic view of the base;

fig. 3 is a schematic diagram of moving plate adjustment.

1-a heater; 2-water bath; 3-a base; 4-a card slot; 5-a pulley; 6, moving a board; 7-large reaction bottle; 8-small reaction bottle; 9-a breather pipe; 10-an air inlet valve; 11-gas outlet valve.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: a preparation method of polymer-based nitrogen and phosphorus doped graphitized porous carbon comprises the following steps:

(1) adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] of P]Octane and triethylamine are slowly dripped with acryloyl chloride at the temperature of between 10 below zero and 0 ℃ below zero in a mass ratio of 170-110-120: 100, the three are stirred at a constant speed for reaction for 5 to 10 hours, the solvent is removed by reduced pressure distillation, ether is used for washing, methanol and distilled water are added for recrystallization and purification, and the molecular formula C is prepared₈H₁₁O₆Acryloylation of P1-phospha-2, 67-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:0.75-1.5:0.12-0.18 by mass ratio into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the reaction is carried out for 10-20h by heating to 75-85 ℃ in a nitrogen atmosphere, solvents are removed by vacuum drying, and the polyacrylonitrile-based macromolecular chain transfer agent is prepared by washing and drying by using distilled.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile according to the mass ratio of 100:20-40:8-15:0.1-0.2 into a reaction bottle, placing the mixture into an atmosphere reaction device, reacting for 12-24h at 80-90 ℃ in a nitrogen atmosphere, drying in vacuum to remove the solvent, washing with distilled water and methanol, and drying to obtain the phosphorus monomer-containing poly (acrylonitrile-styrene) copolymer.

(4) The preparation method comprises the steps of placing a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer in an atmosphere furnace, carrying out pre-oxidation treatment for 3-6h at 280 ℃ in the air atmosphere, then heating to 800 ℃ at 750 ℃ and carrying out high-temperature carbonization treatment for 2-3h to prepare polymer-based nitrogen and phosphorus doped graphitized porous carbon, and applying the polymer-based nitrogen and phosphorus doped graphitized porous carbon to a lithium ion battery cathode material.

Example 1

(1) Adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] of P]Octane and triethylamine are added, acryloyl chloride is slowly dropped at the temperature of 0 ℃, and the mass ratio of the octane to the triethylamine is 170:110:100Stirring at constant speed for 5h, distilling under reduced pressure to remove solvent, washing with diethyl ether, adding methanol and distilled water, recrystallizing and purifying to obtain molecular formula C₈H₁₁O₆Acryloylation of P to 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:0.75:0.12 by mass into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the reaction is carried out for 10 hours by heating to 75 ℃ in a nitrogen atmosphere, solvents are removed by vacuum drying, and the polyacrylonitrile-based macromolecular chain transfer agent is prepared by washing and drying by using distilled.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile according to the mass ratio of 100:20:8:0.1 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 12 hours at 80 ℃ in a nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer.

(4) Placing a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer in an atmosphere furnace, firstly carrying out preoxidation treatment for 3h at 220 ℃ in the air atmosphere, then heating to 750 ℃, and carrying out high-temperature carbonization treatment for 2h to prepare the polymer-based nitrogen and phosphorus doped graphitized porous carbon 1.

Example 2

(1) Adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxyl of PSubstituted-1-phospha-2, 6, 7-trioxabicyclo [2.2.2]Octane and triethylamine are added, acryloyl chloride is slowly dropped at the temperature of minus 5 ℃, the mass ratio of the three is 175:112:100, the mixture is stirred at a constant speed for reaction for 10 hours, the solvent is removed by reduced pressure distillation, the mixture is washed by ether, methanol and distilled water are added for recrystallization and purification, and the molecular formula C is prepared₈H₁₁O₆Acryloylation of P to 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:1:0.14 by mass into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the reaction is carried out for 10 hours by heating to 85 ℃ in a nitrogen atmosphere, solvents are removed by vacuum drying, and the polyacrylonitrile-based macromolecular chain transfer agent is prepared by washing and drying by using distilled.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile in a mass ratio of 100:25:10:0.15 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 18 hours at 85 ℃ in a nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer.

(4) The preparation method comprises the steps of putting a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer into an atmosphere furnace, carrying out pre-oxidation treatment for 4 hours at 250 ℃ in the air atmosphere, then heating to 750 ℃, and carrying out high-temperature carbonization treatment for 3 hours to prepare the polymer-based nitrogen and phosphorus doped graphitized porous carbon 2.

Example 3

(1) Adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] of P]Octane and triethylamine, slowly dripping acryloyl chloride at-5 ℃ in a mass ratio of 185:118:100, uniformly stirring for reacting for 8 hours, distilling under reduced pressure to remove the solvent, washing with diethyl ether, adding methanol and distilled water for recrystallization and purification to obtain the molecular formula C₈H₁₁O₆Acryloylation of P to 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:1.25:0.16 by mass into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the heating is carried out to 80 ℃ in a nitrogen atmosphere, the reaction is carried out for 15 hours, the solvent is removed by vacuum drying, the product is washed and dried by using distilled water and methanol.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile in a mass ratio of 100:32:12:0.17 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 18 hours at 85 ℃ in a nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer.

(4) Placing a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer in an atmosphere furnace, firstly carrying out pre-oxidation treatment for 4h at 250 ℃ in the air atmosphere, then heating to 780 ℃, and carrying out high-temperature carbonization treatment for 2.5h to prepare the polymer-based nitrogen and phosphorus doped graphitized porous carbon 3.

Example 4

(1) Adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] of P]Octane and triethylamine are slowly added with acryloyl chloride dropwise at the temperature of minus 0 ℃ in a mass ratio of 190:120:100, the three are stirred at a constant speed for reaction for 8 hours, the solvent is removed by reduced pressure distillation, the ethyl ether is used for washing, methanol and distilled water are added for recrystallization and purification, and the molecular formula C is prepared₈H₁₁O₆Acryloylation of P to 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:1.5:0.12-0.18 by mass ratio into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the mixture is heated to 85 ℃ in a nitrogen atmosphere and reacts for 20 hours, a solvent is removed by vacuum drying, and the mixture is washed and dried by using distilled water and methanol to prepare the polyacrylonitrile-.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile in a mass ratio of 100:40:15:0.2 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 24 hours at 90 ℃ in a nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer.

(4) Placing a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer in an atmosphere furnace, firstly carrying out preoxidation treatment for 6h at 280 ℃ in the air atmosphere, then heating to 800 ℃, and carrying out high-temperature carbonization treatment for 3h to prepare the polymer-based nitrogen and phosphorus doped graphitized porous carbon 4.

Comparative example 1

(1) Adding dichloromethane solvent with molecular formula of C into a reaction bottle₅H₉O₅4-hydroxymethyl-1-oxo-1-phospha-2, 6, 7-trioxabicyclo [2.2.2] of P]Octane and triethylamine are slowly added with acryloyl chloride dropwise at the temperature of 0 ℃ in a mass ratio of 160:110:100, the three are stirred at a constant speed for reaction for 10 hours, the solvent is removed by reduced pressure distillation, ether is used for washing, methanol and distilled water are added for recrystallization and purification, and the molecular formula C is prepared₈H₁₁O₆Acryloylation of P to 1-phospha-2, 6, 7-trioxabicyclo [2.2.2]An octane derivative.

(2) Adding N, N-dimethylformamide solvent, acrylonitrile, azodiisobutyronitrile and C with the molecular formula of 100:0.5:0.1 by mass into a reaction bottle₉H₁₄O₄S₃The RAFT reagent s, s ' -di (alpha, alpha ' -dimethyl-alpha ' -acetic acid) trithiocarbonate is placed in an atmosphere reaction device, the atmosphere reaction device comprises a heater, a water bath is arranged above the heater, a base is arranged inside the water bath, a clamping groove is fixedly connected above the base, the clamping groove is movably connected with a pulley, the pulley is movably connected with a moving plate, a large reaction bottle and a small reaction bottle are arranged above the moving plate, a vent pipe is arranged above the water bath, two ends of the vent pipe are respectively and movably connected with an air inlet valve and an air outlet valve, the heating is carried out to 80 ℃ in a nitrogen atmosphere, the reaction is carried out for 15 hours, the solvent is removed by vacuum drying, the product is washed and dried by using distilled water and methanol.

(3) Adding an N, N-dimethylformamide solvent, adding styrene, an acryloyl esterified 1-phospha-2, 6, 7-trioxabicyclo [2.2.2] octane derivative, a polyacrylonitrile-based macromolecular chain transfer agent and an initiator azobisisobutyronitrile in a mass ratio of 100:15:6:0.08 into a reaction bottle, placing the reaction bottle in an atmosphere reaction device, reacting for 18 hours at 85 ℃ in a nitrogen atmosphere, vacuum drying to remove the solvent, washing with distilled water and methanol, and drying to prepare the poly (acrylonitrile-styrene) copolymer containing the phosphorus monomer.

(4) Placing a poly (acrylonitrile-styrene) copolymer containing a phosphorus monomer in an atmosphere furnace, firstly carrying out preoxidation treatment for 5h at 220 ℃ in the air atmosphere, then heating to 750 ℃, and carrying out high-temperature carbonization treatment for 3h to prepare polymer-based nitrogen and phosphorus doped graphitized porous carbon contrast 1.

Respectively mixing polymer-based nitrogen and phosphorus doped graphitized porous carbon in the examples and the comparative examples with acetylene black, polyvinylidene fluoride and N-methyl pyrrolidone solvents, coating the mixture on the surface of copper foil, drying and stamping to prepare a negative electrode material of a lithium ion battery, taking a lithium sheet as a positive electrode material and a polypropylene porous membrane as a diaphragm, and 1mol/L LiPF₆The solution is used as electrolyte, a CR2032 button cell is assembled in argon atmosphere, and a constant current charge-discharge test is carried out in a CT2001A cell test system, wherein the test standard is GB/T243358-2019.